An implantable penile prosthetic has an inflatable member that is sized for implantation into a penis of a user, a reservoir that is implantable in an abdomen, and a pump that is intraoperatively attached between the inflatable member and the reservoir. The pump includes a pump bulb having an internal cavity formed by a side surface connected between a bottom surface of the pump bulb and a top surface of the pump bulb. The side surface of the pump bulb provides an outside circumference of the pump bulb and includes at least two concave side walls. Each concave side wall is connected between two adjacent convex lobes of the pump bulb.
